Saturday's annual Earth Day celebration comes at a pivotal moment for a number of global environmental issues.

This year marks the 47th annual Earth Day event, which began on April 22, 1970. According to the campaign's estimate, more than 1 billion people participate in Earth Day festivities every year, making it the largest civic observance in the world.

Environment and pollution-related issues continue to make headlines in the weeks leading up to Earth Day, with major environmental crises across the planet.

South Florida residents wade through high waters in a North Miami parking lot. Earth scientists say climate change is causing the sea level to rise in coastal areas.

Climate change

The Guardian on Monday published its report on a new climate change study stating that unless global fossil fuel output is substantially curbed soon, by the mid 21st century human beings will have achieved a climate change rate not seen for the last 50 million years, back when the Ice Age came to an end.

The effects of this unprecedented rise in temperature continue to be felt around the globe, including the coastal U.S. In South Florida communities like Broward County, ocean water routinely flows up drainage pipes and into the streets during seasonal high tides, theSun Sentinel reported.

Water shortage

U.N. climate scientists say climate change is also partly to blame for the decadeslong drought in parts of sub-Saharan Africa, according to the Independent.

The World Water Council in March declared almost one-third of people in the sub-Saharan region lack access to safe drinking water, the Associated Press reports. That includes Nigeria, South Sudan and Somalia, where water prices have spiked and some locals are forced to walk many miles in search of water as well as food, according to Public Radio International.

Deforestation

Agricultural development in Sub-Saharan Africa since the year 2000 also has caused the region to lose an area of forest about the size of Iceland, according to a recent study published on Phys.org. Farmland development has grown faster in the region than in any other part of the world since 2015, the site reports.

But the sub-continent's deforestation rates pale in comparison to those in South America, where cattle farming in particular has contributed to 70% of the continent's reduction in forests, which contributes to rainfall reductions and increased carbon dioxide emissions.

So-called "ragpicker" women search for recyclables on International Women's Day in Gawahati, India.

Garbage in developing India and Sri Lanka

At least 30 people are confirmed dead this week in Sri Lanka after the Friday collapse of a nearly 300-foot tall garbage mound in a region plagued with years of excessive pollution,India reports.

The collapsing mountain of refuse was so big, it buried more than 100 homes and displaced more than 600 people, the site reports.

"Urban areas in [neighboring] India alone generate more than 100,000 metric tonnes of solid waste per day, which is higher than many countries' total daily waste generation," Sudhakar Yedla of the Indira Gandhi Institute of Development Research writes for East Asian Forum.

A woman wearing a medical mask looks at her smart phone while walking in Beijing.

Air pollution

In September, the World Health Organization published a report stating that nine out 10 people live in countries with excessive air pollution, according to Fortune.

One of the worst offenders is China, whose ongoing battle with air polluters recently went from bad to worse.

A recent increase in industrial activity in the world's most populous nation has contributed to a decline in air quality, according to the Economic Times.

China's Ministry of Environmental Protection says the major cities of Beijing and Guangzhou's number of "blue sky" days, when the atmosphere above an area is relatively clear throughout the day, are down through the first three months of 2017 compared to the same time last year.